A tomographic view of the Gulf Stream southern recirculation gyre at 38°N, 55°W
Chester, David B.
MetadataShow full item record
Reciprocal acoustic transmissions made in a region just south of the Gulf Stream are analyzed to determine the structure and variability of temperature, current velocity, and vorticity fields at the northern extent of the southern recirculation gyre. For ten months (November, 1988 through August, 1989), a pentagonal array of tomographic transceivers was situated in a region centered at 38°N, 55°W as part of the eastern array of the SYNOP (SYNoptic Ocean Prediction) Experiment. The region of focus is one rich in mesoscale energy, with the influence of local Gulf Stream meandering and cold-core ring activity strikingly evident. Daily-averaged acoustic transmissions yielded travel times which were inverted to obtain estimates of range-averaged temperature and current velocity fields, and area-averaged relative vorticity fields. The acoustically determined estimates are consistent with nearby current meter measurements and satellite infrared imagery. The signature of cold-core rings is clearly evident in the sections. Spectral estimates of the fields are dominated by motions with periodicities ranging from 32-128 days. Second-order statistics, such as eddy kinetic energies, and heat and momentum fluxes, are also estimated. The integrating nature of the tomographic measurement has been exploited to shed some light on the radiation of eddy energy from the Gulf Stream. The Eliassen-Palm flux diagnostic has been applied to an investigation of wave radiation from the Gulf Stream. Results of the diagnosis suggest that the Gulf Stream itself is the source of wave energy radiating into the far field and found in the interior of the North Atlantic subtropical gyre.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 1993
Showing items related by title, author, creator and subject.
Waldbauer, Jacob R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-02)Biological activity has shaped the surface of the earth in numerous ways, but life’s most pervasive and persistent global impact has been the secular oxidation of the surface environment. Through primary production – the ...
Temporal variability and vertical structure in larval abundance : the potential roles of biological and physical processes Garland, Elizabeth D. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-02)Recruitment variability in benthic invertebrate populations results from variability in planktonic larval supply and from processes occurring during and after larval settlement onto the seafloor. The focus of this thesis ...
Physiological and behavioral diagnostics of nitrogen limitation for the toxic dinoflagellate Alexandrium fundyense Poulton, Nicole J. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-09)One challenge in phytoplankton ecology is to measure species-specific physiological responses to changes in environmental conditions. Of particular importance in this regard are harmful algal bloom (RAB) species such as ...